A method for converting heat of an external source into mechanical work is known from the prior art (RU, 2078253, IPC6 F 03 G 7/06, 20.04.97), said method allows raising the efficiency of a thermal generating set to a value close to 1, i.e. to the full conversion of heat into mechanical work.
A method realized in the compressor free cycle of the closed gas turbine power plant is known (Leontiev A. I., Shmidt K. L. “Compressor Free Cycle in the Closed Gas Turbine Power Plant//Izvestia RAN. Power Engineering.—1997—No. 3—pp. 132-141), said method is as efficient as the Carnot cycle, in which the additional low-temperature power source (refrigerator) is used. When this method is realized a significant part of the input heat energy is lost in the refrigerator, especially when external heat sources with sufficiently high temperature are used.
A method is known (RU, 2162161, IPC7 F 03 G 7/06, 20.01.2001), upon the realization of which the highest efficiency of the thermal generating set is achieved by complete conversion of the working medium heat received from the external source into mechanical work. This method comprises the interaction of the working medium with a heat energy source, in particular, heat energy from the external power is conferred to a working medium flow, said flow is expanded by mechanical work, and the power interchange with an additional low-temperature heat energy source is performed, for which a part of the general flow of the working medium with elevated density is used.
Essentially this method realizes the process of energy transmission inside the system ‘working medium—additional low-temperature energy source’. The method allows obtaining the efficiency of thermo-mechanical transformations close to 1 and using low-temperature heat energy sources. However, this is possible only due to the use of a special fairly complex system of regenerating heat energy of the working medium expanded after performing a mechanical work.